Add a retry when probing for printers on discovered ports. This is to accomodate for printers that needs a few seconds to initialize before they open the port.

plugins/USBPrinting/AutoDetectBaudJob.py

@@ -22,6 +22,7 @@ class AutoDetectBaudJob(Job):
     def run(self):
         Logger.log("d", "Auto detect baud rate started.")
         timeout = 3
+        tries = 2
 
         programmer = Stk500v2()
         serial = None
@@ -31,36 +32,38 @@ class AutoDetectBaudJob(Job):
         except:
             programmer.close()
 
-        for baud_rate in self._all_baud_rates:
-            Logger.log("d", "Checking {serial} if baud rate {baud_rate} works".format(serial= self._serial_port, baud_rate = baud_rate))
+        for retry in range(tries):
+            for baud_rate in self._all_baud_rates:
+                Logger.log("d", "Checking {serial} if baud rate {baud_rate} works".format(serial= self._serial_port, baud_rate = baud_rate))
 
-            if serial is None:
-                try:
-                    serial = Serial(str(self._serial_port), baud_rate, timeout = timeout, writeTimeout = timeout)
-                except SerialException as e:
-                    Logger.logException("w", "Unable to create serial")
-                    continue
-            else:
-                # We already have a serial connection, just change the baud rate.
-                try:
-                    serial.baudrate = baud_rate
-                except:
-                    continue
-            sleep(1.5)  # Ensure that we are not talking to the boot loader. 1.5 seconds seems to be the magic number
-            successful_responses = 0
+                if serial is None:
+                    try:
+                        serial = Serial(str(self._serial_port), baud_rate, timeout = timeout, writeTimeout = timeout)
+                    except SerialException as e:
+                        Logger.logException("w", "Unable to create serial")
+                        continue
+                else:
+                    # We already have a serial connection, just change the baud rate.
+                    try:
+                        serial.baudrate = baud_rate
+                    except:
+                        continue
+                sleep(1.5)  # Ensure that we are not talking to the boot loader. 1.5 seconds seems to be the magic number
+                successful_responses = 0
 
-            serial.write(b"\n")  # Ensure we clear out previous responses
-            serial.write(b"M105\n")
+                serial.write(b"\n")  # Ensure we clear out previous responses
+                serial.write(b"M105\n")
 
-            timeout_time = time() + timeout
+                timeout_time = time() + timeout
 
-            while timeout_time > time():
-                line = serial.readline()
-                if b"ok T:" in line:
-                    successful_responses += 1
-                    if successful_responses >= 3:
-                        self.setResult(baud_rate)
-                        return
+                while timeout_time > time():
+                    line = serial.readline()
+                    if b"ok T:" in line:
+                        successful_responses += 1
+                        if successful_responses >= 3:
+                            self.setResult(baud_rate)
+                            return
 
-                serial.write(b"M105\n")
+                    serial.write(b"M105\n")
+            sleep(15) # Give the printer some time to init and try again.
         self.setResult(None)  # Unable to detect the correct baudrate.